Party-line telephone system.



VI/YT/VESSES H. HOVLAND.

PARTY LINE TELEPHONE SYSTEM.

APPLICATION FILED OCT. 31. 1912.

Patented 0.01: 26; 1915.

I \HIMHFIHW I 1 ,1l.58,221l.

IIENRY IOVLAND, or LINOOLN, NEBRASKA, ASSIGNOR 'ro AUTOMATIC ELne'rn'Ic COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

PARTY-LINE TELEPHONE SYSTEM.

Specification of Letters Patent.

Patented Uct. an

To all whom if mu i/ conccrn:

Be it known that I, HENRY ITOVLAXD, of the city of Lincoln. in the county of Lancaster and State of Xcbraskafhave invented certain new and useful Improvements in I Party-Line Telephone Systems, of which the following is a specification.

i\I v invention relates to party-line telephone svsteins. and more specifically to an imtwo selected frequencies upon the line, thus proved mechanism whereby, when the call is from one subscriber to another on the same line. the calling subscriber may signalthe, desired called subscriber; A call of this character is oftentimes referred to as a reverting call. and li v my invention I provide a ring-hack device which may be selectively operated l) the calling subscriber so as to select any two of a plurality of ringing generators. ()ne of these generators is of a character such as. will ring the bell at the called suhscrihefis station, while the other generator selected is of a character to ring the belt at the station of the callingsubsci'ilier. l'pon making the call thecalling subscriber automatically.operutes this ringliack device to select the desired pair of ringing generators. and then replaces his receiver upon they switch hook. The ring-back device then automatically starts to operate to alternately throw ringingcurrent of the alternately sounding the bells at the calling and called subscribers stations. Upon the response of-tlie called subscriber the ringing current is disconnected from the line, and .ihus the calling subscriber is advised bv the cessation of the ringing of his hell that the called, suliscril er has answered. lie then againremoves his receiver from the hook and the conversation is carried on in the usual manner.

't'ui-ther. object of my invention isthc' improved lilhllllltl' in which the release ot the riiig-liacl'c' device and the automatic switches 'eiiiployed, in establishing the connection is brought about. As I have above pointed out. when the calling subscriber first replaces his receiver upon the hook and thus opens the line circuit. the ring-backdevice is automatically started in operation. hen, however;

after the called subscriber has responded and the liridgeis again removed from across the line by the hanging up of the receivers at both the calling and called subscribers stations, the ring-back device is released.

' pulse springs These and other objects of my invention will be more readily understood by reference to the accompanying drawings, in, which I have chosen to illustrate my invention in connection with an automatic system of the type in which the connection between subscribers lines is established through the medium of subscribers indivldual or line switches, selectors and connectors. S ch a system being well known in the art, 1'. is not thought necessary to describe the entire system herein, and il have accordingly shown only a sufficient portion thereof to illustrate fully the mode of operation OI my invention.

In the accompanying drawing I have shown diagrammaticallya single polystation subscribers li-ne, together with its individual type. Referring to the substation A, each of the substations shown here n comprises the usual receiver 2, transmitter 3', switch book 4, ringer 5. and condenser 6. Beingan' automatic substation it is also provided with an impulse transmitter or callingdevice which is represented herein by a pair of 1mp t and 8 and a toothed impulse wheel-9. which latter is assumed to be controlled through the medium of a finger hole dial (not shown) in such a manner that the impulse springs 7 and 8 may be momentarily separated a number of times corresponding to each digit of the number tobe called.

The line switchC, which is individual to the line, is of the general type of line switches shown in British patent to It W James No. 20,301 of 1006, being of the particular form shown in British patentto T. G. Martin No. 1419 of 1910. Tl is'line switch, as is well known, comprises a plunger (not shown) which is secured to a socalled plunger arm 11, which latter, when attracted by the magnet 12, causes said plunger to be thrust into one of a plurality of groups of contact springs, each of which groups represents the terminal of a trunk line leading to a selector switch E. The line switch also comprisesa jcut ofi" relay throng ,switch D is of the type of master switches. disclosed in said British Patents Nos. 26,301

of 1906 and 1419 of 1910.

The selector E is of the general type of selector switches disclosed in United States Letters Patent No. 815,321, granted March '13, 19.06, to Keith, Erickson and Erickson, being modified, however, as shown in said BriinshPatent N o. 1419 of 1910, in order to operate in a two-wire system. In general, 7 this switch comprises a bank of contacts arranged in rows or levels and which are adapted to be engaged by a set of wipers 20, 21 and22 which are carried by a vertically end rotatably movable shaft (not shown), the movements of which are controlled by rotary magnets 23 switch comprising 28 is controlled by these-called vertical and and 24. The usual side the wipers 25, 26, 27 and the private magnet 29 in the well-known manner. The usual release magnet is represented at 30. The relays 31 and 32 and 33 are slow acting relays- -that is, relays which denergize slowly after-their energizing circuits have been broken. The ring-back device F comprises among other details two pairs of wipers 41 and 42, and 43 and 44, which are carried upon a rotary shaft and adapted to be advanced step by ste 'over two double rows of contacts the medium of a stepping magnet 35. The magne 36 is a release magnet which, when energized, withdraws a holding pawirmm the shaft of the switch and ale lows' the wipers to be restored to normal "position by a spring in a well-known manner. The contact 37, which is included in the circuit of the release magnet, is controlled by theshaft of the switch so as to be closed only when said shaft is rotated one or more steps from its normal position.

' The operation of the switch is controlled by the calling subscriber through the medium of a double-wound line relay 45. The relays 38 and 39- are relays which deenergize slowly. There are provided in the switch .1 two ringing relays 46 and 46. The apparatus as shown herein is adapted to be used in connection with a four-party line -s ysteni.[ .There are therefore, shown four ringing current generators R, R R? and R, which are assumed to produce ringing current of four different characters. The ringers 5 of the different substations. on the subscribers line may be arranged inany ringing current generated by some particular one of the generators. For instance, the generator R may produce ringing current of the proper character to operate the ringer at the substation A. The generator R may operate the ringer at the substation A the generator R may operate the ringer at the substation A and the generator R may operate the ringer at the fourth substation A? (not shown). The generator R is connected with the first three contacts in the upper double row of contacts of the switch F. The generator R is connected to the fourth and fifth contacts of the upper row and to the first contacts of the lpwer row. The generator R is connected to the sixth contacts of the upper row and to the second and fourth contacts of the lower row. The generator R is connected to the third, fifth and sixth contacts of the lower row. WVith this arrangement, it will be seen that the wipers 41, 42, 43 and 44 may be set so as to connect any two of the generators desired with the springs of the ringing relays 46 and 46% Beneath the selector switch E there is shown an interrupter device H which may be common to'a plurality of frequency selectors F. This device comprises a pair of interrupter wheels 53 and 54 which are driven by means of a motor magnet 55 and ratchet wheel 56. During their rotation the wheels 53 and 54 alternately close the contacts 57 and 58. At 59 there is shown'a continuously operating interrupter for producing impulses for operating the magnet 55'. The operation of the device H is controlled through the medi'um of a double wo'und relay 60. A general description of the apparatus having been given, it.-.will now be explained how one of the subscribers on the partyline may'signal another subscriber on the same line. Since the operations of the line switch 0 and the selector E shown herein are in general well known in the art, and are fully described in the publications hereinabove referred to, it is not thought necessary to give a detailed description of the same herein. In general, the operation of these switches is as follows: Upon the rethe pull-down Winding 15, which latter operates to attract the cut-off armature 13 and the plunger arm 11. This latter operation causes the calling line to be extended through the lineswitch contacts 61 and 62'to the selector E, whereupon itslme wiper 21, side switch wiper 28, contact 62, :thence over the line circuit to and through the calling substation and back over the nectcd the. line winding-17 from the lineand allowed the armature 1a to fall back to open the circuit of the operating winding 15. The closure of the contact 65 upon the operation of the line switch C'causes the master switch D toadvance the plunger-s of the idle line switches of the group to which the switch (3 belongs to an idle trunk line'.- It is assumed herein that some level of the first s lector is reserved for reverting call purposes. 1* or this purpose there is connected to the contacts of this levela pluto a ring-back device F.

rality of trunk'lines, each of which leads The calling subscriber, after ,having obtained connection with the selector E, by the removal of his receiver operates his calling device for the digit corresponding to the level of the selectors to which the ring-back devices are connected. This operation of the substation calling device produces a series of momentary interruptions in the circuit of the selector line relay 63. The operation ofthe relay 63, in response to these impulses,

causes a series of impulses to be transmitted through the vertical magnet 23, whereby the wipers of the selector are raised to a position opposite the level to which the ring-back devices are connected, after which the private magnet 29 causes the side switch to pass'to second position. The rotary magnet 24 is thereuponbrought into play and operates in the usual manner to rotate the wipers onto an idle set of contacts in said level, after which the side switch passes to.

third position.

Upon the engagement of the sideswitch wipers 25 and 28 of the selector with their thirdposition contact points, a circuit is closed through the line relay of the ringback device F. This circuit extends from ground G through the lower winding of said relay, contacts and 50, .selector T other side of the line, through the line switch bank contact 61, side switch wiper 25, shaft wiper 20, contacts 49 and i9 and the upper winding of the relay 45 to the battery lead 66, thence through the battery '13 to ground G. The relay 45, upon enershaft.

I'OVS- flhis' receiver upon the switch-hook, whereby and a holding circuit for the release relay- 31 of" the selector'E. This circuit extends from ground G through the front contact of the springGE) to the private bank contacts of the-selected trunk in all of the selector switches which have access thereto and through the "wiper 22 of the selector E, side switch wiper 26, contact and the relay 31 to the battery lead 66. The relay 39, upon energizing, also closes a circuit eX- tending from ground Gr through the front contact of the spring 69 and thence through the relay 72. Therelay 72, upon energizing, opens the contact '73 in the circuit of the release magnet 36 to prevent the energization of said magnet when the contact 37 is closed upon'the first step of the switch Th calling subscriber must now cause the wipers of the ring-back device F to'be advanced on to the pairs of contacts which are connected to the two ringing current generators which are adapted to produce ringing currents of the proper frequency for-operating the ringers at the calling and called substations. For instance: If the subscriber at the substation A is calling the subscriber at the substation A or vice versa, the wipers 451, 42,- 43 and 44 must be advanced onto their firstcontacts, and therefore intoengagement with the terminals of the generators Rfand R If the wipers to any desired point, the calling subscriber operates his calling device for a digit wvliicli is one less than the number of steps required for the wipers toreach the desired contacts, and then hangsup his receiver. For instancezlt has'been assumed herein that the subscriber at the substation A is calling the subscriber at the substation A 1 The calling subscriber therefore operates his calling device for the digit 1, whereby the circuit of the line relay 45 is interrupted once momentarily. The relay 39 being a slow acting relay does not deenergize during the momentary interruption of its circuit by the deenergization of the relay 45, and

therefore therelay .45, upon deenergizing, transmits an impulse over a circuit extending from ground G through. the back contact of the spring (37, contact 71, stepping magnet 35 and the relay 38 in multiple to the battery lead 66. The operation of the relay 38 at this time is functionless. The

magnet 35 operates in response to this im-.

pulse to advance the wipers 41, d2, 43 andfi i onto thefirst contacts in their respectlvc The calling subscriber now replaces the circuit of the line relay ofthe ring.

back device F is again broken. The relay 45, upon deenergi'zing, again closes the circuit of the stepping magnet'35, whereby the wipers 41, 42, 43 and 44 areadvanced one more step onto'the second contacts in their respective rows. The relay 4 5, in its deenergized' position, also breaks the circuit of ,therelay 39,-which in turn deenergizes after a short time. v

After the relay39 deenergizes, the holding circuits for the relay 72 and for the'release relay 31 of the selector are maintained at, the

contact 74 of the relay .38, which is enera gized by the deenergization of the line relay. The circuit of'the relay 38, as 'well' as that of the stepping magnet 35, is, of course, broken at the contact 71 when the relay'39- 'deenergizesg-but since the relay 38 is a slow acting relay, it maintains the contact 74 closed until another holding circuit for the I relays72 and 31 can be closed in the following manner: Since the relay 38 is'energized when the relay 39 deenerglzes, a circuit is closed extending from ground G through the back contact of the spring 69, contact 75 l of the relay 38' and normally closed contact 76 of the relay 77, thence throughthe relay 78 to the battery lead 66. The relay 78, upon the contact 83 and the winding of the relay.

7 8 to the battery lead 66. In this circuit la'st' traced it will be seen that there is also a circuit extending from ground G through the contacts 79 and 81 to the circuits of the relays 72 and- 31 to maintain them energized after the relay 38- has fallen back and per;- mitted the contact 74'tobe opened. A fur-f ther result of the energization of the relay 78 is the closure of a circuit extending from ground G through the contact 80, and

thence through the windings of the two ring-. ing relays 46 and 46 and through the two windings of the relay to the battery lead 66. The windings of the relay 60 have a comparatively high resistance and do not permit sufiicient current. to fiow'through the ringing relays 46 and 46 to cause them to be operatively energized- The relay 60,

however, is energized and by, closing-the contact 84 completes the circuitof the stepping magnet. 55. The magnet 55 thereupon- -begi is to rotate the ratchet wheel 56. and

interrupter-wheels 54 and 53, whereby the contacts '57 and 58 are alternately closed.

Upon theclosure of the contact 57 the upper winding-of the relay 60 is short-circuited and the ringing relay 46 is operatively energized. In the relay 46 the contacts 47 and 48 are preferably'in'the nature of follow-up contacts, so that as the relay is energized the in the reverse ordcr--that is, the contacts 51 and 52 are broken simultaneously, then the contact 48 is closed, then the contact 47 is closed and finally the contacts 50 and 49 are closed simultaneously. The relay 46 op- .eratesin the same n1anner. Upon energizing, the relay 46 therefore first disconnects the line relay of the ring-back device F from the line by the opening of the contacts 49 and 50. The closure of the contact 47 then short-circuits the line, which, however, is without function at this time. The contact 48 is next opened and this short-circuit broken, then the contacts 52 and 51 are closed, whereby the ringing current generator R is connected with the calling line b way of the wipers 43 and 44. The calling line is therefore supplied with ringing current from theringing current generator R, which, as before explained,- is of the proper characterto operate only the ringer at the calledfor station A After. the interrupter wheels have advanced far enoughto open the contact 57, the ringing relay 46 deenergizes', with the result that after the generator R isdisconnected from the line, the line is then short-circuited during the time the contacts 47 and 48 are both closed and then the short-circuit is removed from the line and the connection between the line and the line relay of the ring-back device is restored.

The objectin short-circuiting the line.

after the ringing current is disconnected therefrom, and before the connection with the relay45 is restored, is toprovide a path for the discharge of the condensers on the calling line, so that they will not-cause a momentary energization of the relay 45. After the ringing relay 46 is deenergized. the contact 58 is closed by the interrupter and the ringing relay 46 is ener ized to connect the ringing current generator with the calling line. This generator R furnishes ringing current of the proper character for operat ing the ringer at the calling substation A. The relays 46 and 46 willcontinue to be alternately energized and deenergized to alternately ring the bells'at the calling and called substations A and-A until the called subscriber responds by removing his receiver from theswitch hookl As'soon as this occurs, or as soon thereafter as the ringing relay deenergizes, if it happens to be energizedat the time, the line relay 45 again becomes energized and by opening the contact 8:2 destroys the holding circuit of the relay 78.

. The relay 77, however, remainscnergized over a circuit extending from ground G through the front contact of the spring 69 of the relay'39, which latter is again energized upon the energization of the relay 45, and through the contact 81 and the winding of the relay 77 to the battery lead 66. The relay 78, upon deenergizing, permanently breaks the circuits of the ringing relays 46 andfl6 to prevent further application of r nging current to the line. The calling subscribers bell therefore ceases to ring, which is an indication to him that the called subscriber has answered, and he removes his receiver again and the twosubscribers now carry on an uninterrupted conversation, the talking current being supplied through the windings -of the line relay'45 over the heavy conductors shown in the drawing.

. The release of the central office apparatus is brought about by'the hanging up ofthe receivers at both the calling and the called substations. When the last receiver is hung up the line relay 45 again deenergizes. Since the relay 77 is locked up at this time, no circuit is closed through the relay 78 by the deenergization of the relay 45, and consequently as soon as the relays '38 and 39 de-' energize, the circuit of the relay-89 being closed by the falling back of the relay 45, as heretofore explained, the circuits of the relays 72 and 31 are broken. The relay 72, upon deenergizing, closes the circuit ofthe release magnet 36 at the contact 73, whereupon said magnet energizes and permits the wipers 4:1, 42, '43 and 4 1' to be restored to their normal positions, whereupon the contact 37 is opened and the magnet 36 permitted to denergize. The deenergization of the relay 31 at the selector E completes a circuit extending" from ground G through the back contact of the spring 87, back contact. of the spring 88, magnet 30 and the contact 89 to the battery lead 66. The magnet 30., upon energizing, permits the shaft of the selector to be restored to normal position,

whereupon the contact 89 is opened and the magnet 30 permitted to deenergize. The re-.

lay 31, upon deenergizing, also opens the circuit of the holding winding 16 of the line switch C at the contact 6 1 and the line switch is permitted to release also.

It will thus be seen that I have devise a very efiicient mechanism for making reverting calls. The calling subscriber has merely to operate his dial to properly opcrate the ring-back device in order to select the two desired'ringing generators, and then,

' .upon replacing his recelver upon the hook,

his bell is sounded to advise him of the fact to devise a system in which. two kinds of ringing current are sent back over thecalling line in order to operate the calling signal at both the calling and the called subscribers stations. Likewise, I believe that I am the first to devise a system in which the opening of the bridge across the calling line at one time is,operative to start the ringing operation, and. at another time is operative to cause the release of the connection. I

While I havefchosen to illustrate my invention in connection with one particular embodiment of the same,it is, of course, to

be understood that I 'do not wish tobe limitedto the exact construction shown and de- I scribed. I

What I claim as my invention is 1. In a telephone system, a party-line, a ring-back apparatus-for enabling one party to call another on the samefdine, means for connecting said line with 'said apparatus, a

plurality of sources of ringing current of different characters, and means controlledby said ring-back apparatus for selecting two of said sources to operate the signals at the calling and called substations.

2. In a telephone system, a party-line, a

two of said generators, and means for alternately supplying current from-said selected generators to said line.

4(In a telephone system, a party-line, a plurality of ringing generators for supply ing ringing current of different characters, a 'step-by-step ring-back apparatus, means for connecting said line with said apparatus, means controlled by the calling subscriber for operating said ring-back apparatus, to

select any two of, said ringing generators, and means for then alternatelyv connecting loo said selected ringing generators with the V line. Y

- 5. In a telephone system, a party-line, a ring-back apparatus for enabling one party to call another on the same line, and means controlled by said ring-back apparatus for transmitting two kinds of ringing current back over said line to operate the calling signal at both the calling and called substations on said line.

6. In a telephone system, a party-1ine,a

ring-back apparatus for enabling one party to call another on the .same line, a plurality czi of ringing of ringing current generators, said ring-back apparatus comprising a pair of wipers, means to operate said wipers to connect each of said wipers with any one ofsaid ring ing current generators, and means to alternatel-y connect said wipers with said line.

7. In a telephone system, a party-line, a ring-back apparatus for to call another on the same line, a plurality of ringing current generators, said ring-back apparatus comprising two pairs of wipers, means for connecting one of said pairs with any one of said ringing generators, 'means for connecting the other pair with any of the remaining then alternately connecting said pairs of wipers with said line. a 8; In a telephone system, ring-back apparatus for enabling one party to call another on the same line, aplurality generators of different characteristics, said ring-back apparatus including a plurality of pairs of wipers, means controlled by the calling subscriber to connect one ofsaidpairs of wipers with the ringing generator'of a characteristic corresponding to the signal at the calling substation and for connecting the other pair of wipers with the ringlng generator of a characteristic corresponding to the called substation, and means for then alternately connecting said pairs of wipers with said line.

9. In a telephone system, a party-line, a ring-back apparatus for enabling one party to call another on the same line,-'means including a selector switch for extending a connection from' said line to said ring-back apparatus, a plurality of sources of ringing current, means controlled by said ring-back apparatus for selecting any 'two of said sources, and means controlled by the replacing of the calling subscribers receiver upon the switch-hook for alternately transmitting current from said two selected generators over said line.

10. In a telephone system, a party-line, a ring-back apparatus for enabling one party to call another on the same line, a bridge across said line, means for opening said bridge to cause said ring-back apparatus to operate to send ringing current on the line While the bridge is open, and. means for opening said bridge at another time to cause the release of said apparatus.

11. In a telephone system, a party-line, a ring-back apparatus for enabling one party to call another on the same line, means including a selector switch for extending a connection from said line to said ring-back apparatus, a bridge on said line controlled by the switch-hook at the calling substation, means controlled by said ring-back apparatus for transmitting ringing current over said line to signal the called subscriber, 'means controlled by the opening of said enabling one partygenerators, and means fora party-line, 'a-

eluding a selector bridge before the called subscriber has answered for starting said ring-back apparatus in operation to send ringing current on the line while the bridge is open, and means controlled by the opening of said bridge after the called subscriber has answered for controlling the release of said connection.

12. In a telephone system, a party-line, a ring-back apparatus for enabling one party to call another on the same line, a plurality of sources of ringing current, means controlled by said ring-back apparatus for selec'ting two of said ringing generators of a character adapted to operate the signal at the calling and called substations on said line, a bridge on said line, means controlled by the opening of said bridge before the called subscriber has responded for operating said ring-back apparatus, and means controlled by the opening of said bridge after the called subscriber has responded for releasing said connection.

13. In a telephone system,.a party-line, a ring-back apparatus for enabling one party to call another'on the same line,-means inswitch 'for extending a connection from "said line to said ring-back apparatus, a bridge on said line controlled by the switch-hook at the calling substation, means controlled by said ringback apparatus for transmitting ringing current over said line to signal the called subscriber,

means controlled by the opening of said bridge at one point before the called subscriber has answered for startmg said r ng- -back apparatus in operation to send ringing current on the line while the bridge is open, and means controlled by the opening of said bridge at the same point after the called subscriber has answered for controlling the release of said connection.

14:. In a telephone system, a line, a second line, means for connecting said first and second lines, a plurality of signals operatively associated with said first line, an -automatic switch for said second line, a signaling circuit for each signal under the control of said switch, means for supplying signaling current to said circuits, and an impulse .sender for operating said automatic switch 16. In a telephone system, a line, a second line, a palr of signals for said first line, means for connecting the hnes, a signallng circuit for each signal, means for supplying slgnaling current to said signaling circuits,

automatic means for associating said signal mg circuits with the connected circuit while the two lines are connected, and an impulse sender for controlling said automatic means signaling circuit for. each signal, means for supplying signaling current to said circuits, and automatic means for selecting any two of SELld'ClI'CUltS and for associating the selected signaling circuits 'with the connected circuit while the said two line circuits are connected. 1

18. In a telephone system, a line, a second line, a plurality of signals for said first line, means for connecting the two lines, a signaling circuit for each signal, means for supplying signaling current to said circuits, automatic means for selecting any two of said circuits and for associating the selected signaling circuits with the connected circuit while the said two lines are connected,

and an impulse sender for controlling said automatic means over the second line for the purpose set forth.

19. In a telephone system, a line,a second line, a pair of'signals for'said first line,

means for connecting the lines, a signaling circuit for each signal, means for supplying signaling current tosaid signaling circuits, and automatic means for associating said signaling circuits with the connected circuit while the two lines are connected, said auto matic means having equipment for controlsignaling current to said signaling circuits,

automatic means for associating said signaling". circuits. with the connected circuit while the two lines are connected, and an impulse sender for controlling said automatic means over the second line for the purpose set forth, said automatic means having equipment for controlling said signaling c1rcuits for operating said signals while the first and second lines are connected.

21. In a telephonesystem, a line, a second line, a pair of signals for said first line,

means for-connecting the lines, a signaling circuit for-each signal, means for supplying signaling current to 'sald slgnahng circuits and automatic means for associating said signaling circuits with the connected circuit while the two lines are connected, said automatic means having equipmentfor controlling said signaling circuits for operating said signals alternatelywhile the first and second lines are connected.

22. In a telephone system, a line, a second line, a pair of signals for said first line, means for connecting the lines, a signaling c rcuit for each signal, means for supplying signaling current to said signaling circuits, automatic means for associating said signalmg circuits with the connected circuit while the. two lines are connected, and an impulse sender for controlling said automatic means over the second line for the purpose set forth, said automatic means having equipment for controlling said signaling circuits for operating said signals alternately while the first and second lines are connected.

23. In a telephone system, a line, a second line, a plurality of signals for said first line, means for connecting the two lines, a signaling circuit for each signal, means for supplying signaling current to said circuit, and automatic means for selecting any two of said circuits and for associating the selected signaling circuits with the connected circuit while the said two lines are connected, said automatic means having equipment for controlling the selected signaling cirmeans for connecting the two lines, a signaling circuit for each signal, means for supplying signaling current to said circuits. automatic means for selecting any two of said circuits and for associating the selected signaling circuits with the connected circuit while the said two lines are connected, and an impulse sender for controlling said automatic means over the second line for the purpose set forth, said automatic means havline, a plurality of signals for said first line, v

ing equipment for controlling the selected slgnaling circuits for operating the corre sponding signals.

25. In a telephone system, a'line, a second line, a plurality of signals for said first line, means for connecting the two lines, a signaling circuitfor each signal, means for supplying signaling current to said circuits, and automatic means for selecting any two of said circuits and for associating the selected signaling circuits with the connected circuit while the said two lines are connected, said automaticmeans having equipment for controlling the selected signaling circuits foroperating the corresponding signals alter I nately.

'26. In a telephone system, a line, asecond 'line, a plurality of signals for said first line,

means for connecting the two lines, a signaling circuit for each signal, means for supplying signaling current to said circuits, automatic means for selecting any two of said circuits and for associating the selected ltd nected circuit while the said signaling circuits with the connected cir cuit while the said two lines are connected,

and an impulse sender for controlling said automatic means over the second line for the'purpose set forth, said automatic means having equipment for. c0ntroll ing the selected signaling circuits for operating the corresponding signals alternately.

27. In a telephone system, a line, a second- "line, a plurality of signals for said first line,

, the selected signaling circuits with the connected. circuit while the-said two lines are ,connected, and an impulse sender for controlling sald automatic means over the second line for the purpose set forth.

' 29. In a telephone system, a line, a second line, a plurality of signals for said first line,

means for connecting the two lines, a signaling circuit for each signal, means for supplying signaling current to said circuits, and automatic means for selecting a plurality of said signaling circuits and for associating the selected signaling circuits with the connected circuit while the said two lines are connected, said automatic means having equipment for controlling said signaling circults for operating said signals while thefirst and second lines are connected.

30.- In a telephone system, a. line, a second line, a plurality of signals for said first line, means for connecting the two lines, a signaling circuit for each signal, means for sup,-

plying signaling current to'said circuits, and

ing circuit for each automatic means for selecting a plurality of said signaling circuits and for associating the selected signalingpircuits with the connected circuit while the said two lines are connected, and an impulse sender for controlling said automatic means over the second line for the purpose set forth, said automatic means having equipment for controlling said signaling circuits for operating said signals alternately while the first and second lines are connected. 31. In a telephone system, a line, a second f line, a plurality of signals for'said first line,

means for connectingthe two lines, a signalsignal, means for supplying signaling current to said circuits, and automatic means for selecting a plurality of said signaling circuits and for associating the selected signaling circuits with the con- .nected circuit while the said two lines are connected, and an impulse sonderfor controlllng said automatic means over the second line for, the purpose set forth, saidautomatic means having equipment for con- .trolling the selected signaling circuits for operating the corresponding signals.

32. In a telephone system, a line, a second line, a plurality of signals for said first line, means for, connecting the two lines, a signaling circuit for each signal, means for supplying signaling current to said circuits, and automatic means for selecting a plurality of said, signaling circuits andfor associating the selected signaling circuits with the connected circuit while the said two lines are connected, and an impulse sender for controlling said automatic means over the sec ond line for the purpose set forth, said automatic means having equipment for controlling the selected signaling circuits for operating the corresponding signals alternately.

Signed by me at Lincoln, Lancaster v county, Nebraska, this 19th day of October,

' HENRY HOVLAND. IVitnesses NVM. L. LEMON,

SAMUEL E. VVITT. 

